Sune Luus calmly negotiates the rest of the over and that will be lunch. Issy Wong and Lauren Bell, and one apiece for the senior duo of Nat Sciver and Kate Cross.

Marizanne Kapp and Sune Luus did well to see it out until lunch, but that concludes a dominant morning session for England.

Kapp dropped on 14published at 28.1 overs

28.1 overs

Oh! Issy Wong extracts some extra pace and bounce from the pitch and the ball rears up to take the edge of Kapp's bat and the ball flies between Kate Cross and Sophie Ecclestone in the slip cordon.

A tough chance - it went rapidly, but a chance nonetheless.

The ball races away for four but thankfully, Wong is still smiling.

Kapp steps across her stumps and cuts Ecclestone into the covers for two, with Sophia Dunkley, fielding at close cover, having to take evasive action.

Kapp edges one between the slips for two before there's a half-hearted lbw appeal from the final ball that was very optimistic, the ball drifting down the leg side.

Wong still causing some problems out there, the added pace perhaps a contributing factor.

Stephan Shemilt
BBC Sport chief cricket writer at Taunton

Marizanne Kapp has not only given that the kitchen sink. She's given it the taps, the plates and everything else.

Shot! Issy Wong offers some width to Kapp and she crunches it through the off side for a boundary.

She doesn't even run, just stands and admires her work. Have that.

Sophie Ecclestone has two close catchers in and bravely tosses the ball up to Marizanne Kapp, who produces a glorious drive that is well stopped for just a single.

A big 10 minutes before lunch coming up for the visitors.

Stephan Shemilt
BBC Sport chief cricket writer at Taunton

There's a big breeze blowing left to right it should help Ecclestone get drift in towards the right handers and bring captain Heather Knight at slip in to the game.

Heather Knight is enjoying the bowling options she has at her disposal as she brings Issy Wong back into the attack.

Another fine over concedes just two. Debut nerves? No chance.

A rare loose ball from Ecclestone drifts onto Kapp's pads and she clips it away for two, but to absolutely nobody's surprise, it's a fine start from the spinner.

The challenge gets even harder for South Africa as Sophie Ecclestone is on for the first time.

Not the bowler you want to be facing when you're four wickets down in the first session.

Nat Sciver gets one to zip from nowhere to slice Sune Luus in half and Amy Jones is completely baffled by it through no fault of her own and the ball races away for four byes.

Luus follows it with a glorious back foot punch for four and another two driven through the covers - a profitable over for the visitors.

Here's the wicket of opener Lara Goodall.

Look at Nat Sciver's face in the celebration - she cannot believe that was turned down originally!

That'll do nicely! Marizanne Kapp gets off the mark with a beautifully timed cut off Lauren Bell as the seamer just loses her line and length.

Kapp will be wanting a few more of those to put away before lunch.

Georgia Elwiss
England all-rounder on BBC Test Match Special

What I'd like to see from Kapp and Luus is show some more intent. Maybe walking at the bowler and continuing to rotate the strike. England are bowling well at the moment being attacking and aggressive so South Africa are doing well absorbing the pressure which is something they need to do right now.

Marizanne Kapp navigates another probing Nat Sciver maiden.

Pressure, pressure, pressure ...

Feast your eyes on this.

Issy Wong's first Test wicket. What a celebration, what a prospect.

Melissa Story
BBC Test Match Special

These players are used to the shorter format especially the young bowlers. There's a bit of a curse on these seam bowlers in England with both Katie George and Tash Farrant in the women's game. You feel they want to be careful with Issy Wong and Lauren Bell especially with the amount of white ball cricket to come this summer.

Another fine maiden from Lauren Bell.

This is going to be a challenge for South Africa's batters to get through until lunch without losing any further wickets as the ball is still swinging. There's a lot of responsibility on Sune Luus' shoulders, as the captain.

Sune Luus eases the pressure slightly with a firm drive down the ground but it's well saved by Issy Wong and they scamper through for three runs.

The sun is beaming down on Taunton now and many of the woolly jumpers we saw earlier have been removed, although there is still a slight breeze. England are buzzing in the field.